1. Field of the Invention
This invention is directed to a lock for an automobile shock absorber to permit raising of the wheel without full shock absorber extension.
2. Description of the Prior Art
In present automotive practice, the body of the car is sprung with respect to the wheels and axles. This springing provides some isolation from road irregularities. The amount of isolation depends upon the mass of the sprung body and the spring constant and each application includes compromises because perfect isolation is not obtainable at all frequencies.
In undamped systems, the excursions of the sprung automobile body would become excessive, uncomfortable, and even dangerous to proper control of the vehicle. Thus it is conventional to apply shock-absorbing or damping devices between the sprung and the unsprung structures. The modern shock absorber is conventionally a circular cylinder with a piston therein, together with a damping fluid and damping orifice between the sides of the piston. Such a structure absorbs energy and prevents uncontrolled oscillations.
It sometimes becomes necessary with the modern automobile to change wheels, usually due to the fact that one of the tires has become flat. The jack usually supplied with modern automobiles jacks up the automobile body to the full extension of the spring between the wheel and the body until the wheel in question to be repaired is raised from the ground. Since the normal shock absorber is simply a shock-absorbing structure, it does not control the height of the wheel. Efforts have been made to provide shock absorber structures which lock, such as shown in Schultze U.S. Pat. No. 3,559,776, which provides a rigid suspension system for off-road vehicle use. This is accomplished hydraulically and is very complicated. Fennell U.S. Pat. No. 2,917,321 shows a shock absorber locking structure, but it is mechanically operated from a jacking position and is only lockable at discrete positions so that it does not reach the full capability of locking the shock absorber at the best position.